# Physics CH18 and CH 19

Topics: Force, Electric charge, Potential energy Pages: 4 (732 words) Published: June 21, 2014
Name ____________________________________Equipotential

Go to http://phet.colorado.edu/simulations/sims.php?sim=Charges_and_Fields and click on Run Now.
Complete Part 1 for chapter 18 and part 2 and 3 for chapter 19. Part 1: What is an equipotential line and how is this simulation related to work and energy? 1) Turn on “Show Numbers”
2) Place a positive 1 nano-coulomb charge near the center of the screen. 3) In the lower left of the screen is a meter for indicating electric potential, in volts, created by the charge that you introduced. Record the voltage and turn on “Plot”. 3.7V

4) This line is much like a line on a geologic topo map. Explain the similarity.

These two are sounded by the curve.

5) You are on the side of a hill with a topo map of the region. If you walked so that your trip follows a topo line you would be doing no work on your backpack. Why?.

Because on that line the height is the same, therefore, there will be no work on the backpack.

6) If a second charge were placed on this line (don’t do it), how much work is need to move it along the line?

Potential is defined that it is equal to minus the work done, and it doesn't change if it's an equipotential. The force and field are at right angles to an equipotential surface.

7) Move the meter closer to the charge at the center of the screen. What is the new electric potential? Turn on plot again 3.9V

8) Remember that electric potential is energy per charge (1 volt = 1 Joule/Coulomb). Is electric potential a vector or a scalar? Scalar

9) If a second positive charge were introduced and moved from the first equipotential line created to the second line (closer to the charge), would this involve positive or negative work? 13) Explain.

10) If the second positive charge were moved away from the first Positive charge, would this involve positive or negative work.

Negative work because as the second charge gets close to the first charge,...